October 12, 2005

EU study suggests PCBs may damage human sperm

LONDON (Reuters) - Toxic man-made industrial chemicals in
the environment can damage sperm but do not seem to
dramatically effect male fertility, scientists said on

They tested the impact of polychlorinated biphenyls (PCBS),
so called gender bending chemicals which are blamed for causing
genetic abnormalities in fish, but found no serious threat to

The damage to sperm increased with the level of exposure to
the chemicals in European men but did not have the same effect
on 193 Inuits men from Greenland in the study.

"We can only speculate, at this stage, that genetic make-up
and/or lifestyle factors seem to neutralize or counterbalance
the pollutants in this group," Dr Marcello Spano, of the
Italian National Agency for New Technologies, Energy and the
Environment (ENEA) said in the statement.

PCBs are mixtures of synthetic organic chemicals that have
been used in hundreds of industrial and commercial

More than 1.5 billion pounds of PCBs were made in the
United States before production was stopped in 1977, according
to the U.S. Environmental Protection Agency.

Spano and his colleagues tested the amount of DNA damage in
the sperm of 700 men from Sweden, Poland, Ukraine and Greenland
in the European Union project.

They also measured levels of a marker in blood samples for
PCBs in the body and questioned the men about their lifestyle,
occupation and reproductive history.

The median level of damaged sperm DNA in the men was 10
percent and the large majority of men in that group were
fertile. The odds of fathering a child start to diminish when
damaged sperm reaches 20 percent, according to the scientists.

"PCB exposure might negatively impact reproductive
capabilities especially for men who, for other reasons, already
have a higher fraction of defective sperm," Spano said.

The scientists, whose findings are reported online by the
journal Human Reproduction, said more research is needed into
the effects of PCBs, a class of compounds that includes 200
toxic by-products.

They also stressed the need for more information on the
impact of exposure of unborn babies which could be more
relevant to health and reproductive consequences.

(Reporting by Patricia Reaney; editing by Stephen Weeks;
Reuters Messaging: [email protected]))